ABO blood group and esophageal carcinoma risk: from a case–control study in Chinese population to meta-analysis

Purpose The association between ABO blood group and the risk of esophageal carcinoma (EC) in previously published studies is uncertain and conflicting. The aim of the current study was to determine the correlation of ABO blood group with EC risk via a case–control study and meta-analysis. Methods We performed a population-based case–control study of 3,595 cases and 41,788 controls in Chinese population to evaluate the association between ABO blood group and EC risk. Then, a comprehensive meta-analysis combining our original data and previously published data was conducted to clearly discern the real relationship. The strength of association was measured by odds ratios (ORs) with 95 % confidence intervals (CI). Results In our case–control study, the risk of EC in blood group B was significantly higher than that in non-B groups (A, O, and AB) (OR = 1.15, 95 % CI 1.09–1.21). Compared with non-O groups (A, B, and AB), individuals with blood group O demonstrated a reduced risk of EC (OR = 0.90, 95 % CI 0.85–0.94). The meta-analysis also indicated that blood group B was associated with significantly higher EC risk (OR = 1.20, 95 % CI 1.10–1.31), and people with blood group O had a decreased EC risk (OR = 0.94, 95 % CI 0.90–0.99). Neither the case–control study nor the meta-analysis produced any significant association of blood group A or AB with EC risk. Conclusion Results from our case–control study and the followed meta-analysis confirmed that there was an increased risk of EC in blood group B individuals, whereas a decreased risk of EC was observed in blood group O individuals.